Recent studies have demonstrated that calcium dobesilate, ethamsylate and persilate exert effects on the endothelium in the sense of facilitating endothelium-dependent vascular relaxation. This effect is observed both in normal animals and in those in which vascular aging has been produced experimentally by means of the administration of high doses of vitamin D.sub.2. This activity of calcium dobesilate, of ethamsylate and of persilate may be reflected in man by effects which are therapeutically useful. In particular, it has been demonstrated that the erection of the penis is modulated by nitric oxide produced in the endothelium (A. L. Burnett et al., Science, 1992, 257, 401-403; J. Rajfer et al., N. Engl. J. Med., 1992, 326, 90-94; Editorial, Lancet, 1992, 340, 882-883) and that, under circumstances where the endothelial function is detrimentally affected, as in hyperlipidemias (K. Kugiyama et al., Nature, 1990, 344, 160-162), correction of the detrimental change normalizes the erectile function, measured with accuracy during nocturnal sleep (J.-B. Kostis et al., J. Clin. Pharmacol., 1994, 34, 989-996; R. C. Rosen, "The Pharmacology of Sexual Function and Dysfunction", edited by J. Bancroft, Elsevier Sc., 1995, pages 277-287). The normalization of the endothelial function obtained with calcium dobesilate, ethamsylate and persilate can represent an entirely novel therapeutic approach to the problem of impotence (I. Saenz de Tejada et al., N. Engl. J. Med., 1989, 320, 1025-1030), both in patients with vascular disorders with various causes (diabetes, arteriosclerosis, and the like) and in patients where only a functional disorder can be detected.
Furthermore, the normalizing effect on the endothelial function can also offer therapeutic opportunities in vascular spasm processes, in complications of diabetes (W. Durante et al., Br. J. Pharmacol., 1988, 94, 463-468) and in all disorders, including premature ejaculation (E. M. Hull et al., Neuropharmacology, 1994, 33, 1499-1504), where a deficit in the formation of nitric oxide for the vascular endothelium appears evident.